My initial response is “a” link is both not much of threat and potentially difficult to detect. A pattern of such links is both easier to detect and should be easier to detect.
But to directly answer the question, I know of no tool that specifically monitors for malicious links in the same way that anti virus software monitors for malicious software code.
You can however obtain a list of every inbound link to your website that Google knows about.
Use Google Search Console (formerly known as Google Webmasters Tools) and look at the following report:
Then under “Your most linked content” select “More”.
To see a larger image, click within the image.
After you select More you will have an opportunity to download the table you’re viewing if you desire, but that’s not where the answers you want lie.
When you click into examine the source of links to specific page, you see the domains from which the links originate. So in theory it is possible to monitor for potentially malicious links, but it’s a very time consuming process.
Might there be a commercial opportunity for someone to write such a tool merely by loading the data available from Google Search Console into a database and allowing different views of the data?
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